use locale;
use strings;

// The information from a desktop entry file.
export type file = struct {
	typ:                     str,
	version:                 str,
	name:                    locale::string,
	generic_name:            locale::string,
	no_display:              bool,
	comment:                 locale::string,
	icon:                    locale::string,
	hidden:                  bool,
	only_show_in:            []str,
	not_show_in:             []str,
	dbus_activatable:        bool,
	try_exec:                str,
	exec:                    str,
	path:                    str,
	terminal:                bool,
	actions:                 []str,
	mime_type:               []str,
	categories:              []str,
	implements:              []str,
	keywords:                locale::strings,
	startup_notify:          bool,
	startup_wm_class:        str,
	url:                     str,
	prefers_non_default_gpu: bool,
	single_main_window:      bool,
};

// Parses a desktop entry file. Use [[file_finish]] to get rid of it.
export fn parse(input: io::handle) (file | error) = {
	let state = parse_state { ... };
	let scanne = scan(input);
	defer finish(&scanne);
	
	for (let entr => next_entry(&scanne)) {
		match(parse_handle_entry(entr)) {
		case let err: error =>
			file_finish(&state.file);
			return err;
		case void => void;
		};
	};
};

// Frees resources associated with a [[file]].
export fn file_finish(file: &file) void = {
	free(file.typ);
	free(file.version);
	locale_string_finish(file.name);
	locale_string_finish(file.generic_name);
	locale_string_finish(file.comment);
	locale_string_finish(file.icon);
	strings::freeall(file.only_show_in);
	strings::freeall(file.not_show_in);
	free(file.try_exec);
	free(file.exec);
	free(file.path);
	strings::freeall(file.actions);
	strings::freeall(file.mime_type);
	strings::freeall(file.categories);
	strings::freeall(file.implements);
	locale_strings_finish(file.keywords);
	free(file.startup_wm_class);
	free(file.url);
};

type parse_state = struct {
	file: file,
};

fn parse_handle_entry(this: *parse_state, entr: entry) (void | error) =  {
	if (entr.group != "Desktop Entry") return void;
	
	if (entr.key == "Type") {
		if parse_is_localized(entr) return void;
		this.typ = parse_string(entr.value)?;
	} else if (entr.key == "Version") {
		if parse_is_localized(entr) return void;
		this.version = parse_string(entr.value)?;
	} else if (entr.key == "Name") {
		parse_set_locale_string(
			*this.name, entr.locale,
			parse_localestring(entr.value)?)?;
	} else if (entr.key == "GenericName") {
		parse_set_locale_string(
			*this.generic_name, entr.locale,
			parse_localestring(entr.value)?)?;
	} else if (entr.key == "NoDisplay") {
		if parse_is_localized(entr) return void;
		this.no_display = parse_boolean(entr.value)?;
	} else if (entr.key == "Comment") {
		parse_set_locale_string(
			*this.comment, entr.locale,
			parse_localestring(entr.value)?)?;
	} else if (entr.key == "Icon") {
		parse_set_locale_string(
			*this.icon, entr.locale,
			parse_iconstring(entr.value)?)?;
	} else if (entr.key == "Hidden") {
		if parse_is_localized(entr) return void;
		this.hidden = parse_boolean(entr.value)?;
	} else if (entr.key == "OnlyShowIn") {
		if parse_is_localized(entr) return void;
		this.only_show_in = parse_strings(entr.value)?;
	} else if (entr.key == "NotShowIn") {
		if parse_is_localized(entr) return void;
		this.not_show_in = parse_strings(entr.value)?;
	} else if (entr.key == "DBusActivatable") {
		if parse_is_localized(entr) return void;
		this.dbus_activatable = parse_bool(entr.value)?;
	} else if (entr.key == "TryExec") {
		if parse_is_localized(entr) return void;
		this.try_exec = parse_string(entr.value)?;
	} else if (entr.key == "Path") {
		if parse_is_localized(entr) return void;
		this.path = parse_string(entr.value)?;
	} else if (entr.key == "Terminal") {
		if parse_is_localized(entr) return void;
		this.terminal = parse_boolean(entr.value)?;
	} else if (entr.key == "Actions") {
		if parse_is_localized(entr) return void;
		this.actions = parse_strings(entr.value)?;
	} else if (entr.key == "MimeType") {
		if parse_is_localized(entr) return void;
		this.mime_type = parse_strings(entr.value)?;
	} else if (entr.key == "Categories") {
		if parse_is_localized(entr) return void;
		this.categories = parse_strings(entr.value)?;
	} else if (entr.key == "Implements") {
		if parse_is_localized(entr) return void;
		this.implements = parse_strings(entr.value)?;
	} else if (entr.key == "Keywords") {
		parse_set_locale_strings(
			*this.keywords, entr.locale,
			parse_localestring(entr.value)?)?;
	} else if (entr.key == "StartupWMClass") {
		if parse_is_localized(entr) return void;
		this.startup_wm_class = parse_string(entr.value)?;
	} else if (entr.key == "URL") {
		if parse_is_localized(entr) return void;
		this.url = parse_string(entr.value)?;
	} else if (entr.key == "PrefersNonDefaultGPU") {
		if parse_is_localized(entr) return void;
		this.prefers_non_default_gpu = parse_bool(entr.value)?;
	} else if (entr.key == "SingleMainWindow") {
		if parse_is_localized(entr) return void;
		this.single_main_window = parse_bool(entr.value)?;
	};
};

fn parse_is_localized(entr: entry) bool = {
	return !locale::equal(entr.locale, locale::c);
};

fn parse_set_locale_string(dest *locale::string, local: locale::locale, value: str) void = {
	for (let existing &.. *dest) {
		if (locale::equal(existing.0, locale)) {
			existing.1 = value;
			return;
		};
	};
	append(*dest, (locale::dup(local), strings::dup(value)));
};

fn parse_set_locale_strings(dest *locale::strings, local: locale::locale, value: []str) void = {
	for (let existing &.. *dest) {
		if (locale::equal(existing.0, locale)) {
			existing.1 = value;
			return;
		};
	};
	append(*dest, (locale::dup(local), strings::dupall(value)));
};

fn locale_string_finish(string: locale::string) void = {
	for (let pair .. string) {
		locale::finish(pair.0);
		free(pair.1);
	};
	free(string);
};

fn locale_strings_finish(strings: locale::strings) void = {
	for (string .. strings) locale_string_finish(string);
};